We have studied the adsorption of elemental sulfur on TiO 2 (110) for exposure at room temperature and at 300°C. Depending on the substrate temperature we found different adsorption sites with scanning tunneling microscopy (STM). At room temperature sulfur adsorbs on the titanium rows with a high mobility along the [001] direction. At 300°C sulfur adsorbs at the position of the bridging oxygen ...

A little cooperation goes a long way: The cooperative Brønsted/Lewis acid-base supramolecular catalysts formed in situ from simple chiral magnesium(II) binaphtholate aqua complexes promoted the highly enantioselective 1,4-hydrophosphinylation of α,β-unsaturated esters with diaryl phosphine oxides and 1,2-hydrophosphonylation of α,β-unsaturated ketones with dialkyl phosphites (see scheme).

In this work, we report the degradation of NOx using two catalysts prepared by coating activated carbon from orange peels with TiO2. This study compared the performance of TiO2coated catalysts prepared by CVD (AC1/TiO2) and the sol-gel method (AC2/TiO2). The catalysts were characterized by X-ray diffraction, BET surface area and TEM. The photocatalytic activity was measured by studying the degr...

Supported olefin polymerization catalysts can prevent reactor-fouling problems and produce uniform polymer particles. Constrained geometry complexes (CGCs) have less sterically hindered active sites than bis-cyclopentadienyl metallocene catalysts. In the literature, micrometer-sized silica particles were used for supporting CGC catalysts, which might have strong mass transfer limitations. This ...

New trimetallic magnesium complexes were synthesized for bifunctional catalysis. Complex catalysed ε-caprolactone polymerizations in not only a 'living' manner but also in an 'immortal' fashion. Additionally, tri-Mg was active for the coupling of CO(2) with cyclohexene oxide (CHO) on addition of n-Bu(4)NBr co-catalysts to give cis-cyclohexene carbonate under mild conditions.

The catalytic properties of modified Au/TiO₂ catalysts for low-temperature CO oxidation are affected by deactivation and reactivation after long-term storage and by redox treatments. The effect of these phenomena on the catalysts was studied by HRTEM, BET, SEM, FTIR CO, XPS and H₂ TPR methods. The main cause for the deactivation and reactivation of catalytic properties is the variation in the e...

Background & objectives: Because of its very high solubility, nitrate penetrates easily into soil and underground waters. Surface waters such as lakes, reservoirs, and rivers are exposed to nitrate pollution. Photocatalytic processes have a high potential for nitrate removal due to complete oxidation, lack of formation of multi-cycle metabolites and the availability of catalysts. The purpose of...

OBJECTIVES This study evaluated the effect of magnesium dietary deficiency on bone metabolism and bone tissue around implants with established osseointegration. MATERIALS AND METHODS For this, 30 rats received an implant in the right tibial metaphysis. After 60 days for healing of the implants, the animals were divided into groups according to the diet received. Control group (CTL) received a...

CO2 reforming of methane (CRM) over unpromoted and potassium promoted Ni/Al2O3 catalysts was studied. The catalysts were prepared by impregnation method and characterized by X-ray diffraction (XRD), N2 adsorption (BET), temperature programmed reduction (TPR), temperature programmed oxidation (TPO) and scanning electron microscope (SEM) techniques. The obtained results showed that addition of K2...

The waste tyres represent a source of energy and valuable hydrocarbon products. Waste tyres were pyrolysed catalytically in a batch reactor under atmospheric pressure. The effects of basic catalysts (MgO and CaCO3) were studied on the pyrolysis products. The distribution ratio of gas, liquid and char with MgO and CaCO3 were 24.4:39.8:35.8 wt % and 32.5:32.2:35.2 wt % r...